CA2719287A1

CA2719287A1 - Disposable pants-type diaper

Info

Publication number: CA2719287A1
Application number: CA2719287A
Authority: CA
Inventors: Toshifumi Otsubo
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2008-03-26
Filing date: 2009-03-17
Publication date: 2009-10-01
Also published as: WO2009119376A1

Abstract

The present invention aims to provide a disposable pants-type diaper preventing the diaper's skin in the vicinity of external genital and/or in the vicinity of anus from being soiled with body waste.

A crotch region (6) of a disposable pants-type diaper (1) includes a bodily fluid absorbent structure (45) comprising a liquid-pervious inner sheet, a liquid-impervious outer sheet and a bodily fluid absorbent core and, in addition, a body waste retaining space (31) formed by the inner sheet and the innermost sheet member (120) interposed between the inner sheet and the diaper wearer's skin. Segments (33c, 34c) of the innermost sheet member (120) defining peripheral edges (33b, 34b) of a front opening (33) and a rear opening (34) face to each other in a front-back direction (A) and are bonded to each other via two spacers (71, 71) spaced from each other in a transverse direction (B) to form a space (50). A portion of the innermost sheet member (120) extending between the segments (33c, 34c) sags toward the lowermost portion (6a) of the crotch region (6) to form a separator (20a).

Description

S P E C I F I CAT I O N
DISPOSABLE PANTS-TYPE DIAPER
TECHNICAL FIELD

[0001]

The present invention relates to disposable pants-type diapers preventing the wearer's skin from being soiled with urine and/or feces.

RELATED ART

[0002]
It is well known to provide diapers with a structure serving to prevent urine and feces from being mixed with each other inside the diaper put on the wearer's body.

[0003]

For example, the diaper described in JP 2002-11044 A
(PATENT DOCUMENT 1) has a skin-contact sheet above a liquid-pervious inner sheet covering an absorbent structure wherein, in a crotch region, the skin-contact sheet is formed with an opening and provided with an elastic member attached under tension thereto to surround this opening. In the case of this diaper of prior art, the absorbent structure in the crotch region is formed with a dam-like ridge to block flow of urine and/or feces.

[0004]

In the case of the disposable pants-type diaper described in JP 2007-296314 A (PATENT DOCUMENT 2) , a sheet piece defining a separator serving to prevent urine and feces from being mixed with each other is provided in the crotch region and this sheet piece is fixed along the opposite side edges thereof to the inner surface of the diaper. The sheet piece has a front end and a rear end both extending in the transverse direction of the diaper and these two ends are integrated together on a center line bisecting a width dimension of the diaper.

PATENT DOCUMENT 1: JP 2002-11044 A
PATENT DOCUMENT 2: JP 2007-296314 A
DISCLOSURE OF THE INVENTION

PROBLEM TO BE SOLVED BY THE INVENTION

[0005]

In the case of the diaper described in PATENT DOCUMENT
1, feces move to the inner sheet through the opening of the skin-contact sheet. The skin-contact sheet extends across the crotch region of the diaper in the front-back direction and therefore feces did not properly pass through the opening will flow forward on the skin-contact sheet until the diaper wearer's external genital may be soiled with feces. Furthermore, urine may flow rearward on the skin-contact sheet until the wearer's skin may be soiled with urine in the vicinity of the wearer's anus.

[0006]
In the case of the diaper described in PATENT DOCUMENT
2, the front end and the rear end of the sheet piece defining the separator are bonded to each other along the center line of the diaper, allowing urine and feces to be separated from each other. With this diaper of prior art, feces would not move forward along the separator. However, considering that the separator for anus and external genital is the integrated front and rear ends, it has sometimes been difficult for this separator to block a flow of loose passage.

[0007]
In view of the problem as has been described above, it is a principal object of the present invention to improve the disposable pants-type diaper so that the diaper wearer's skin in the vicinity of external genital and/or anus would not be soiled by body waste flowing in the direction from anus to external genital or the inverse direction.
MEASURE TO SOLVE THE PROBLEM

[0008]

The object set forth above is achieved, according to the present invention, by an improvement in the disposable pants-type diaper having a front-back direction, a transverse direction and a vertical direction being orthogonal one to another and comprising a crotch region, a front waist region extending forward from the crotch region and a rear waist region extending rearward from the crotch region wherein the crotch region includes a bodily fluid absorbent structure comprising a liquid-pervious inner sheet, a liquid-impervious outer sheet and a bodily fluid absorbent core sandwiched between the inner and outer sheets and curved with the inner sheet inside and the crotch region is additionally formed with a separator adapted to separate urine and feces from each other.

[00091 The improvement according to the present invention is characterized in aspects as follow. An innermost sheet member bonded to the inner sheet to be interposed between a pants-type diaper wearer's skin and the inner sheet is adapted to be partially spaced upward from the inner sheet in the vertical direction and thereby to form a body waste retaining space wherein the innermost sheet member includes a front opening allowing urine to flow into the body waste retaining space and a rear opening allowing feces to move into the body waste retaining space. A portion of the innermost sheet member extending between the front opening and the rear opening in the front-back direction sags toward a lowermost portion of the crotch region and is bonded to itself in segments thereof opposed to each other in the front-back direction to form the separator.

[0010]

The present invention has three aspects from first to third as described below.

[0011]
In the first aspect of the present invention, the innermost sheet member is bonded to the inner sheet and segments of the innermost sheet member defining at least respective parts of peripheral edges of the front opening and the rear opening and opposed to each other in the front-back direction are bonded together via a pair of spacers spaced from each other in the transverse direction to define a space having a required dimension.

[0012]

In a preferable embodiment of the first aspect, each of the two spacers is formed of a flexible and elastic material.
[0013]

In another preferable embodiment of the first aspect, each of the two spacers has a dimension in a range of 1 to 30mm in the front-back direction and is spaced from each other by a distance in a range of 5 to 70mm in the transverse direction.
[0014]

In the second aspect of the present invention, the bodily fluid-absorbent structure has side f laps f ormed outboard of the core in the transverse direction and end flaps formed outboard of the core in the vertical direction. A region of the innermost sheet member extending between the front opening and the rear opening is folded along a fold line extending in the transverse direction and defined by a center line bisecting a dimension of the diaper in the transverse direction with a skin-facing surface of the innermost sheet member inside so that the region extending between the front and rear opening and folded to face itself and partially bonded together and the innermost sheet member extends downward from this bonded region toward the inner sheet in the vertical direction to form the separator. The innermost sheet member further includes elastic regions adapted to be elastically contractible and respectively defined between the region facing itself in the front-back direction and partially bonded together and a top of the front opening as viewed in the vertical direction and between the region facing itself in the front-back direction and partially bonded together and a top of the rear opening as viewed in the vertical direction, on one hand, and a non-elastic region defined by a portion extending downward from the bonded regions, on other hand.

[0015]
In a preferable embodiment of the second aspect, the elastic regions extend in the transverse direction in the crotch region and joined under tension to the side flaps of the bodily fluid-absorbent structure.

[0016]
In another preferable embodiment of the second aspect, the innermost sheet member is pant-shaped.

[0017]

In another preferable embodiment of the second aspect, the side flaps are provided with elastic members extending in the front-back direction attached under tension thereto and the elastic regions intersect and overlap the elastic members.
[0018]

In another preferable embodiment of the second aspect, the elastic regions and the elastic members are bonded together in regions of intersecting and overlapping.

[0019]

In the third aspect of the present invention, a portion of the innermost sheet member extending in the front-back direction between the front opening and the rear opening is folded to be opposed to each other in the front-back direction and directly or indirectly bonded to itself along a center line extending in the transverse direction and bisecting a dimension of the diaper in the front-back direction so that the portion droops down toward the crotch region and a lower end thereof is joined to the inner sheet to form the separator. The separator is provided along the center line with a sheet member having a thickness in the front-back direction in a range of 1 to 10mm, a width in the transverse direction in a range of 10 to 70mm and a height in the vertical direction in a range of 30 to 100% of a dimension of the separator in the vertical direction and functioning to restrict a degree of deformation potentially occurring in the separator formed of the innermost sheet material.

[0020]

In a preferable embodiment of the third aspect, the sheet member has a level of stiffness in a range of 40 to 130N based on Procedure D of Stiffness Measuring Method specified by Section 6 of JIS K 6400-2.

[0021]

In another preferable embodiment of the third aspect, the sheet member is attached to the separator on a front surface of the separator, a rear surface of the separator or between the opposed and joined portions of the innermost sheet member.
EFFECT OF THE INVENTION

[0022]
In the disposable pants-type diaper according to the present invention, the innermost sheet member sags toward the lowermost portion of the crotch region to form the separator adapted to separate urine and feces from each other and thereby to prevent urine and feces from being mixed with each other.
[0023]

In one aspect of the disposable pants-type diaper according to the present invention, is bonded to itself via the spacers along a segment of the peripheral edge of the front opening and a segment of the peripheral edge of the rear opening both for the body waste retaining space to form the space of a required dimension. The portion of the innermost sheet member extending in the front-back direction between these segments of the respective openings' peripheral edges sags toward the lowermost portion of the crotch region. The portion of the innermost sheet member sagging in this manner serves as the barrier functioning to prevent urine excreted on the front half of the crotch region and feces excreted on the rear half of the crotch region from being mixed with each other. With the pants-type diaper put on the wearer's body, the segments of the respective openings' peripheral edges defining the space therebetween are put in close contact with the wearer's crotch skin and thereby serve as the barriers against urine flowing rearward and loose passage flowing forward along the wearer's skin. In consequence, the wearer's skin in the vicinity of anus would not be soiled with urine and the wearer's skin in the vicinity of external genital would not be soiled with feces.
[0024]

In one aspect of the disposable pants-type diaper according to the present invention, the innermost sheet member is formed with the front opening and the rear opening and, in the crotch region, the portion of the innermost sheet member extending between these two openings is folded downward and partially joined together to form the separator. The separator serves to prevent urine passing through the front opening and feces passing through the rear opening from being mixed with each other on the liquid-pervious inner sheet. The innermost sheet member further includes elastic regions adapted to be elastically contractible and respectively defined between the region facing itself in the front-back direction and partially bonded together and a top of the front opening as viewed in the vertical direction and between the region facing itself in the front-back direction and partially bonded together and a top of the rear opening as viewed in the vertical direction, on one hand, and a non-elastic region defined by a portion extending downward from the bonded regions, on the other hand. With such unique arrangement, with the diaper put on the wearer's body, the presence of the innermost sheet member would not contract the crotch region in the transverse direction to disengage the side edges of the crotch region from the wearer's inguinal region. In this embodiment, the diaper wherein the innermost sheet member is pant-shaped facilitates the front and rear openings to be aligned with the wearer's external genital and anus, respectively, when the diaper is put on the wearer's body.
In the embodiment of the present invention wherein the elastic regions adapted to be contractible in the transverse direction intersect with the elastic members provided along the side flaps of the bodily fluid-absorbent structure, these elastic regions cooperate with the elastic members to assure reliable fitness of the diaper around the wearer's thighs. In the embodiment of the present invention wherein the innermost sheet member and the side flaps are bonded together in the regions of intersecting and overlapping, the side flaps are smoothly curved along the side edges of the core so that the side flaps may be smoothly put in contact with the wearer's inguinal region.

[0025]

In one aspect of the disposable pants-type diaper according to the present invention, the innermost sheet member forming the separator adapted to separate urine and feces from each other and thereby to prevent urine and feces from being mixed with each other is provided with the sheet member having a thickness in the front-back direction in a range of 1 to 10mm, a width in the transverse direction in a range of 10 to 70mm and a height in the vertical direction in a range of 30 to 100%
of a dimension of the separator in the vertical direction and functioning to restrict the separator from being deformed.
With this arrangement, the separator can fulfill its primary function without being readily crooked even if the diaper wearer's posture changes in various ways. The separator provided with this sheet member serves also to restrict the bodily fluid-absorbent core from being crooked to be pressed against the diaper wearer's skin. In this way, the separator is able to prevent the internal volume of the body waste retaining space from being unacceptably reduced due to such crooking of the core.

BRIEF DESCRIPTION OF THE DRAWINGS
[0026]

[FIG. 1] Fig. 1 is a partially cutaway perspective view of an exemplary embodiment of the pants-type diaper according to the present invention.

[FIG. 2] Fig. 2 is a plan view showing the pants-type diaper having front and rear waist regions thereof unsealed from each other and flatly developed.

[FIG. 3] Fig. 3 is a sectional view taken along the line III-III in Fig. 1.

[FIG. 4] Fig. 4 is an overhead view of the pants-type diaper as viewed from above in a direction indicated by the arrows IV-IV
in Fig. 3.

[FIG. 51 Fig. 5 is a partially cutout perspective view of one preferred embodiment of the pants-type diaper according to the present invention.

[FIG. 61 Fig. 6 is a sectional view taken along the line VI-VI
in Fig. 5.

[FIG. 7] Fig. 7 is a partially cutaway perspective view of an embodiment of the disposable pants-type diaper according to the present invention.

[FIG. 81 Fig. 8 is a sectional view taken along the line VIII-VIII in Fig. 7.

[FIG. 9] Fig. 9 is a partially cutaway plan view of the diaper having been flatly developed.

[FIG. 10] Fig. 10 is a view similar to Fig. 9, illustrating one preferred embodiment of the present invention.

[FIG. 11] Fig. 11 is a partially cutaway perspective view of an embodiment of the pants-type diaper according to the present invention.

[FIG. 121 Fig. 12 is a plan view showing the pants-type diaper having front and rear waist regions thereof unsealed from each other and flatly developed.

[FIG. 13] Fig. 13 is a sectional view taken along the line XIII-XIII in Fig. 11.

[FIG. 14] Fig. 14 is an overhead view of the pants-type diaper as viewed from above in a direction indicated by the arrows XIV-XIV in Fig. 13.

[FIG. 15] Fig. 15 is a partially cutout perspective view of one preferred embodiment of the pants-type diaper according to the present invention.

[FIG. 16] Fig. 16 is a sectional view taken along the line XVI-XVI in Fig. 15.

[FIG. 17] Fig. 17 is a view similar to Fig. 16, showing another preferred embodiment of the present invention.
IDENTIFICATION OF REFERENCE NUMERALS USED IN THE DRAWINGS
[0027]

1 pants-type diaper 2 inner sheet 3 outer sheet 4 absorbent core 6 crotch region 6a lowermost portion of crotch region 7 front waist region 8 rear waist region chassis 12 leg-openings 10 13 peripheries of leg-openings innermost sheet member 20a separator 21 portion of innermost sheet member (front end) 22 portion of innermost sheet member (rear end) 15 31 body waste retaining space 33 front opening 33b peripheral edge 33c segment (lower segment) 34 rear opening 20 34b peripheral edge 34c segment (lower segment) 36 portion extending in front-back direction 45 liquid-absorbent structure 50 void space 71 spacers 120 innermost sheet member 201 pants-type diaper 206 crotch region 207 front waist region 208 rear waist region 220 innermost sheet member 220a tuck (separator) 222 bodily fluid-absorbent structure 222a side flaps 223a end flaps 223 inner sheet 224 outer sheet 231 body waste retaining space 231a body waste retaining space 231b body waste retaining space 231t opening's top 232t opening's top 233 front opening 234 rear opening 237 joint (joint region) 271 elastic region 272 elastic region 273 non-elastic region 301 pants-type diaper 302 inner sheet 303 outer sheet 304 absorbent core 306 crotch region 306a lowermost portion of crotch region 307 front waist region 308 rear waist region 310 chassis 312 leg-openings 320 innermost sheet member 320a separator 331 body waste retaining space 333 front opening 334 rear opening 335 lower end 345 liquid-absorbent structure 381 sheet member (deformation restricting sheet) A front-back direction B transverse direction C vertical direction K dimension of separator in vertical direction L height M width N thickness Q-Q folding line (transverse center line) P-P center line (longitudinal center line) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028]

Details of one or more embodiments of the disposable pants-type diaper according to the present invention will be more fully understood from the description given hereunder with reference to Figs. 1-6.

[0029]

Fig. 1 is a partially cutaway perspective view showing the disposable pants-type diaper 1 as put on the wearer's body wherein a front-back direction, a transverse direction and a vertical direction of the diaper 1 are respectively indicated by double-headed arrows A, B and C which are orthogonal one to another. The pants-type diaper 1 includes a pant-shaped chassis 10 comprising a liquid-pervious inner sheet 2, a liquid-impervious outer sheet 3 and a bodily fluid-absorbent core 4. The chassis 10 has a crotch region 6, a front waist region 7 extending forward from the crotch region 6 and a rear waist region 8 extending rearward from the crotch region 6. The front and rear waist regions 7, 8 are put flat and sealed together along respective pairs of side edges 7a, 7a and 8a, 8a of these waist regions 7, 8, more specifically, at joints 9 arranged intermittently in the vertical direction as viewed in Fig. 1 along these side edges 7a, 7a and 8a, 8a and thereupon a waist-opening 11 and a pair of leg-openings 12 are formed.
Along a periphery lla of the waist-opening 11, a plurality of waist elastic members 14a extending in a circumferential direction is sandwiched between the inner and outer sheets 2, 3 and bonded under tension to at least one of the inner and outer sheets 2, 3. Along a periphery of each of the leg-openings 12, a plurality of leg elastic members 14b extending in the circumferential direction is sandwiched between the inner and outer sheets 2, 3 and bonded under tension to at least one of these inner and outer sheets 2, 3. Three components, i . e . , the leg elastic members 14b and the inner and outer sheets 2, 3 cooperate together to define respective annular elastic regions 41 surrounding the wearer's legs. Of the pants-type diaper 1, at least the crotch region 6 includes a bodily fluid absorbent structure 45 comprising the inner and outer sheets 2, 3 and the absorbent core 4 sandwiched therebetween. The bodily fluid absorbent structure 45 extends in the front-back direction A

and curves convexly downward to define a bottom portion 6a of the crotch region 6.

[0030]

Fig. 2 is a partially cutaway perspective view showing the pants-type diaper la as after the front and rear waist regions 7, 8 of the diaper 1 have been unsealed at the joints 9 and flatly developed as a whole in the front-back direction A as well as in the transverse direction B wherein such developed diaper la is shown as viewed from its inner side. In the state of such developed diaper la, the chassis 10 in Fig. 1 appears as a concave shaped flattened chassis 10a. The periphery lla of the waist-opening 11 in Fig. 1 appears herein as a front end 7b and a rear end 8b of the flattened chassis 10a and the peripheries 13 of the respective leg-openings 12 appear herein as the crotch region's side edges 13b of the flattened chassis 10a. While the crotch region's side edges 13b convexly curve toward a center line P-P extending in the front-back direction A to bisect a dimension of the flattened chassis 10a in the transverse direction X, the respective pairs of side edges 7a, 7a and 8a, 8a of the front and rear waist regions 7, 8 extend generally in parallel to this center line P-P. The absorbent core 4 also is concave shaped and is formed of a mixture 4a of fluff pulp fibers and super-absorbent polymer particles wrapped with a bodily fluid-absorbent and highly dispersant wrapping sheet 4b such as a tissue paper. In the flattened chassis 10a, the innermost sheet member 20 made of hydrophobic sheet material, more preferably, hydrophobic and liquid-impervious sheet material is attached to inner sheet 2 defining the inner surface of the flattened chassis 10a in the crotch region 6 so that the innermost sheet member 20 may define a separator 20a (See Fig.
3). Such flatly developed diaper la is formed symmetrically about the center line P-P extending in the front-back direction A. The lowermost portion 6a of the crotch region 6 lies on a transverse center line Q-Q bisecting a dimension of the flatly developed diaper la in the front-back direction A.

[0031]

The innermost sheet member 20 is attached to the flattened chassis 10a so that the innermost sheet member 20 may be interposed between the inner sheet 2 and the diaper wearer's skin (not shown) when the pants-type diaper 1 is put on the wearer's body. The innermost sheet member 20 has side edges 23 respectively fixed to the crotch region's side edges 13b by hot melt adhesive 24, a front end 21 lying before the lowermost portion 6a of the crotch region 6 and extending in the transverse direction B between the side edges 23, 23 and a rear end 22 lying behind the lowermost portion 6a of the crotch region 6 and extending in the transverse direction B between the side edges 23, 23. The innermost sheet member 20 in the illustrated embodiment is not bonded to the inner sheet 2 and adapted to be spaced from the inner sheet 2 except the side edges 23 so that a tunnel- or pocket-like body waste retaining space 31 extending from the front end 21 to the rear end 22 may be defined between the innermost sheet member 20 and the inner sheet 2.
Along the front end 21 and the rear end 22, the innermost sheet member 20 is folded back to form a sleeve 21a and a sleeve 22a, respectively. These sleeves 21a, 22a contain therein a front elastic member 21b and a rear elastic member 22a attached under extension thereto, respectively, to define front elastic region 42 and a rear elastic region 43 both extending between the crotch region's side edges 13b. These elastic regions 42, 43 intersect with the elastic regions 41 of the flattened chassis 10a. A
distance Hf from the transverse center line Q-Q to the front end 21 is generally equal to a distance Hr from the transverse center line to the rear end 22.

[0032]
The innermost sheet member 20 is provided on the front end 21 with a pair of spacers 71 located symmetrically about the center line P-P extending in the front-back direction A and spaced from each other by a dimension M. Each of the spacers 71 may be provided in the form of a block made of a sponge, a foamed polyurethane, a foamed polystyrene, a foamed polyethylene, a felt or a nonwoven fabric each having a flexibility sufficient to be easily deformed under a body weight of the wearer of the pants-type diaper 1 and, more preferably, having an elastic recovery properties also sufficient for a rapid recovery after deformation. The innermost sheet member 20 is provided on the rear end 22 with a pair of regions 72 indicated by imaginary lines which are also located symmetrically about the center line P-P extending in the front-back direction A and spaced from each other by a dimension M in the transverse direction B. The pair of spacers 71 are bonded to the innermost sheet member 20 at the pair of regions 72 indicated by the imaginary lines as the side edges 7a, 7a and 8a, 8a of the flattened chassis la are joined together to obtain the pants-type diaper 1 (See Figs. 3 and 4).

[00331 Fig. 3 is a sectional view taken along the line III-III
in Fig. 1 and the line III-III corresponds to the center line P-P extending in the front-back direction A in Fig. 2. In the pant-shaped flattened chassis 10, the front and rear waist regions 7, 8 are joined together along the respective side edges 7a, 7a and 8a, 8a thereof . The crotch region 6 curves in U-shape as viewed in the front-back direction A and the lowermost portion 6a of the crotch region 6 defines a bottom of this U-shaped curve. The crotch region's side edges 13b appear in Fig. 3 as the peripheral edges 13 defining the leg-openings 12.

The innermost sheet member 20 has the front end 21 and the rear end 22 thereof bonded to each other via the spacers 71 and the portion 36 shown in Fig. 2 to extend in the front-back direction A between the front end 21 and the rear end 22 sags toward the lowermost portion 6a to form the separator 20a partitioning the crotch region 6 into a front half and a rear half. Each of the spacers 71 has a dimension N in the front-back direction A and is attached to the innermost sheet member 20 by adhesion or sealing. The presence of the spacers 71 allows the front end 21 and the rear end 22 to leave between them a space 50 (See Fig. 4) having a dimension N along the center line P-P extending in the front-back direction A. The regions in which the spacers 71 are joined to the rear end 22 are designated by a reference numeral 72. The separator 20a may be formed so that the portion 36 of the innermost sheet member 20 is put close to, or in contact with or joined to the lowermost portion 6a or the inner sheet 2 in the vicinity of the portion 6a. Fig. 3 exemplarily shows one of these three manners of implementation in which the portion 36 of the innermost sheet member 20 is joined to the lowermost portion 6a or the inner sheet 2 in the vicinity of the portion 6a. In the body waste retaining space 31 formed by cooperation of the innermost sheet member 20 with the inner sheet 2, the front end 21 is spaced from the inner sheet 2 to define a front opening 33 and the rear end 22 is spaced from the inner sheet 2 to define a rear opening 34.

[00341 Fig. 4 is an overhead view of the pants-type diaper 1 of Fig. 1 as viewed from above the waist-opening 11 in a direction indicated by the arrows IV-IV in Fig. 3. As viewed in the transverse direction B of the pants-type diaper 1, the front end 21 and the rear end 22 of the innermost sheet member 20 respectively have central segments 21c, 22c defined between a pair of the spacers 71, right-hand segments 21R, 22R adapted to be put in contact with a right leg of the diaper wearer (not shown) and left-hand segments 21L, 22L adapted to be put in contact with a left leg of the diaper wearer. The central segments 21c, 22c extend in parallel to each other in the transverse direction B to form a space having a dimension N in the front-back direction A and a dimension M in the transverse direction B. These central segments 21c, 22c are adapted to come in contact with the diaper wearer's skin between his or her external genital and anus as the pants-type diaper 1 is put on the wearer's body. The right-hand segments 21R, 22R
cooperate with each other to define a laterally facing V-shaped space so that the wearer' s right leg may be guided through this laterally facing V-shaped space. In a similar manner, the left-hand segments 21L, 22L cooperate with each other to define a laterally facing V-shaped space so that the wearer's left leg may be guided through this laterally facing V-shaped space. As illustrated, the respective leg-openings 12 of the chassis 10 have a right leg peripheral edge 13R and a left leg peripheral edge 13L. The respective peripheral edges 13R, 13L comprise upper segments 15a not overlapping the side edges 23 of the innermost sheet member 20 and lower segments 15b overlapping the side edges 23 and bonded thereto (See Fig. 3 also) . In Fig.
4, respective ranges of these upper segments 15a and lower segments 15b are indicated by double-headed arrows G and H.
[0035]

Sequence in which the pants-type diaper 1 may be put on the wearer's body will be described below together with behavior of the pants-type diaper. First, the front and rear waist regions 7, 8 of the chassis 10 may be spaced from each other in the front-back direction A and then the waist-opening 11 may be sufficiently broadened as seen in Figs. 1 and 4. Thereby the front end 21 of the separator 20a formed of the innermost sheet member 20 is deformed so that the right-hand segment 21R
and the left-hand segment 21L are curved in V-shape facing forward in the front-back direction A around a pair of the spacers. In a similar manner, the rear end 22 is deformed so that the right-hand segment 22R and the left-hand segment 22L
are curved in V-shape facing rearward in the front-back direction A (See Fig. 4) . Consequently, the front opening 33 and the rear opening 34 for the body waste retaining space 31 are automatically broadened (See Fig. 3) . The left-hand segments 21L, 22L are spaced from each other in the front-back direction A at the same moment that the right-hand segments 21R, 22R are spaced from each other in the front-back direction A.
The respective central segments 21c, 22c of the front end 21 and the rear end 22 cooperate together to define the space 50.

Now the diaper wearer (not shown) may guide his or her right leg into an opening 41R for the right leg defined by the upper segment 15a of the right leg peripheral edge 13R, the right-hand segment 21R of the front end 21 and the right-hand segment 22R
of the rear end 22. Then the wearer may guide his or her right leg into the leg-opening 12 for the right leg defined by the upper segment 15a and the lower segment 15b of the right leg peripheral edge 13R. Without interruption, the wearer may guide his or her left leg into an opening 41L for the left leg defined by the upper segment 15a of the left leg peripheral edge 13L, the left-hand segment 21L of the front end 21 and the left-hand segment 22L of the rear end 22. Then the wearer may guide his or her right leg into the leg-opening 12 for the left leg defined by the upper segment 15a and the lower segment 15b of the left leg peripheral edge 13L-[003 61 In the pants-type diaper 1 after it has been put on the wearer's body, the peripheral edges 13 of the respective leg-openings 12, i.e., the right leg peripheral edge 13R and the left leg peripheral edge 13L are elastically contractible in a circumferential direction thereof, on one hand, and the front end 21 and the rear end 22 of the separator 20a are elastically contractible in the transverse direction B, on the other hand. With such arrangement, the upper segment 15a of the peripheral edge 13R for the right leg and the right-hand segments 21R, 22R of the separator 20a are elastically put in close contact around the right leg in the vicinity of the right leg's inguinal region to form a primary seal 51R (See Fig. 4) serving to prevent leak of bodily fluids . Below the primary seal 51R, the lower segment 15b and the upper segment 15a of the peripheral edge 13R for the right leg are integrated to form a secondary seal 52R (See Fig. 4) serving to prevent leakage of bodily fluids. Function of this secondary seal 52R is similar to that of the leg seal in the conventional pants-type diaper. The arrangement and function as have been described just above are also true with respect to the left leg.

Specifically, the upper segment 15a of the peripheral edge 13L
for the left leg and the left-hand segments 21L, 22L of the separator 20a are elastically put in close contact around the left leg in the vicinity of the left leg's inguinal region to form a primary seal 51L serving to prevent leakage of bodily fluids. Below the primary seal 51L, the lower segment 15b and the upper segment 15a of the peripheral edge 13L for the left leg are integrated to form a secondary seal 52L serving to prevent leak of bodily fluids. The pants-type diaper 1 having been put on the wearer' s body may be sufficiently pulled up along the body to assure that the central segments 21c, 22c in the separator 20a come in contact with the wearer's skin between the wearer's external genital and anus.

[00371 With the pants-type diaper 1 put on the wearer's body in the state as has been described above, the portion 36 of the separator20ais positioned to divide the wearer's crotch region into a front half and a rear half. In the front half of the wearer's crotch region, the wearer's external genital lying before the front end 21 is exposed in the front opening 33 and, in the rear half of the wearer's crotch region, the wearer's anus lying behind the rear end 22 is exposed in the rear opening 34. Consequentially, it is assure that urine discharged by the wearer flows through the front opening 33 into the pocket-like body waste retaining space 31 and feces excreted by the wearer moves through the rear opening 34 into the body waste retaining space 31. In this way, it is possible for the pants-type diaper 1 to prevent urine and/or feces from coming in contact with the wearer's skin by the presence of the separator 20a. In addition, the central segments 21c, 22c of the separator 20a is kept spaced from each other in the font-back direction A to define dual barriers adapted to prevent urine from flowing along the wearer's skin toward the anus and simultaneously to define dual barriers adapted to prevent loose passage from flowing along the wearer's skin toward the wearer's external genital as long as these central segments 21c, 22c are kept in contact with the wearer's skin. Furthermore, even if these central segments 2 1c, 22c are not kept in contact with the wearer's skin, these central segments 21c, 22c are adapted to prevent loose passage flowing back from the body waste retaining space through the rear opening 34 to the wearer's external genital, for example, when the wearer sits flat on the floor unless the loose passage flows beyond the space 50. In other words, with the pants-type diaper 1 the wearer's skin in the vicinity of the anus would not be stained with urine and wearer's skin in the vicinity of the external genital would not be soiled with loose passage. Urine and feces once retained in the body waste retaining space 31 can no more flow on the inner sheet 2 in the front-back direction A and be mixed with each other since the separator 20a is kept close to or in contact with or bonded to the inner sheet 2 at the lowermost portion 6a of the crotch region 6. Therefore fluidity of feces would not increase due to mixture with urine and the wearer' s skin would not be readily soiled with such loose passage. In addition, for the wearer's legs, the primary seals 51R, 51L and the secondary seals 52R, 52L are formed to prevent urine and/or feces from readily leaking out of the pants-type diaper 1 even if urine and/or feces do not flow into the body waste retaining space 31 but flowing along the wearer's legs.
[0038]

In the pants-type diaper 1, the front end 21 of the innermost sheet member 20 defining the separator 20a partially defines the peripheral edge of the front opening 33. As viewed in the front-back direction A, the front end 21 lies behind the wearer's external genital and positioned so that the external genital can be reliably exposed in the front opening 33. While the front end 21 is exemplarily illustrated to extend linearly in the transverse direction B, it is also possible to form the front end 21 to curve convexly toward the transverse center line Q-Q. The rear end 22 of the innermost sheet member 20 partially defines the peripheral edge of the rear opening 34. As viewed in the front-back direction A, the rear end 22 lies before the wearer's anus and positioned so that the anus can reliably face the rear opening 34. While such rear end 22 is exemplarily illustrated to extend linearly in the transverse direction B, it is possible to form the rear end 22 to curve convexly toward the transverse center line Q-Q.

(0039]

For the present invention, the shape of the spacers 71 defining the space 50 is not specified in particular. While the dimension N of the spacer 71 is not specified but depends on whether the pants-type diaper 1 is for baby or for adult, for comprehensive application, the dimension N is preferably in a range of 1 to 30mm and more preferably in a range of 1 to 5mm. The dimension N exceeding 30mm will progressively make it difficult to expose the wearer's external genital in the front opening 33 and to expose the wearer's anus in the rear opening 34. A distance dimension M between a pair of the spacers 71 is preferably in a range of 5 to 70mm and more preferably in a range of 25 to 30mm. The distance dimension M smaller than 5mm may sometimes make it difficult for body waste to pass through the space 50 and the distance dimension M exceeding 70mm may sometimes unacceptably broaden the width of the crotch region 6.

[0040]

In the crotch region 6 of the flattened chassis 10a shown by Fig. 2, the inner and outer sheets 2, 3 put flat together define side flaps 25 outboard of the liquid-absorbent core 4.

When the crotch region 6 is curved in U-shape under contraction of the elastic regions 41 and thereupon the pants-type diaper 1 is put into the state as illustrated by Fig. 1, the side flaps 25 behave to raise themselves along side edges 4c of the core 4 in the vicinity of the transverse center line Q-Q, i.e., in the vicinity of the lowermost portion 6a of the crotch region 6. The innermost sheet member 20 having the side edges 23 bonded to the inner surface of the elastic regions 41 pulls the side flaps 25 inward in the transverse direction of the pants-type diaper 1, i.e., toward the center line P-P extending in the front-back direction as the waist-opening 11 is broadened. In consequence, the behavior of the side flaps 25 to raise themselves is further enhanced. Such behavior of the side flaps becomes further significant as the front end 21 and the rear end 22 elastically contract. The side flaps 25 having such behavior come in close contact with the wearer's thighs from below with respect to the pants-type diaper 1 and thereby effectively prevent bodily fluids from leaking out along the wearer's thighs.

[0041]

To implement the present invention, liquid-pervious sheet material such as nonwoven fabric or perforated plastic film may be used as the inner sheet 2. Liquid-impervious sheet material such as plastic film or composite sheet consisting of plastic film and nonwoven fabric may be used as the outer sheet 3. Fluff pulp fibers or a mixture of fluff pulp fibers and super-absorbent polymer particles wrapped with an appropriate sheet material such as a tissue paper may be used as the liquid-absorbent core 4. A hydrophobic sheet material such as a nonwoven fabric or plastic film, more preferably, a hydrophobic and liquid-impervious sheet material may be used as the innermost sheet member 20. While the innermost sheet member 20 are preferably provided along the front end 21 and the rear end 22 with the elastic members 21b, 22b attached under tension thereto so that the innermost sheet member 20 may be elastically contracted, it is possible to eliminate use of the elastic members 21b, 22b by using an elastic sheet material adapted to be elastically contracted in the transverse direction B as the innermost sheet member 20. It should be appreciated that the present invention includes an embodiment according to which both the front end 21 and the rear end 22 are not elastically contractible in the transverse direction B.

[0042]

Fig. 5 is a partially cutaway perspective view of one preferred embodiment of the pants-type diaper 1 according to the present invention. Regions and members of this embodiment similar to those in the pants-type diaper 1 of Fig. 1 are designated with similar reference numerals. Specifically, the pants-type diaper 1 of Fig. 5 also has the crotch region 6, the front waist region 7 and the rear waist region 8 wherein the side edges 7a, 7a and 8a, 8a of the front and rear waist regions 7, 8 are put flat and sealed together at the joints 9 arranged intermittently in the vertical direction to form the waist-opening 11 and a pair of the leg-openings 12. The pants-type diaper 1 according to this embodiment also includes the innermost sheet member 120 facing the wearer' skin (not shown) and a bodily fluid absorbent member 122 attached to the outer surface 120b of the innermost sheet member 120 wherein these innermost sheet member 120 and the bodily fluid absorbent member 122 are integrated with each other to form the pant-shaped chassis 10. The innermost sheet member 120 is preferably hydrophobic, more preferably hydrophobic and liquid-impervious. Elasticized sheet pieces 52 are bonded under tension to the inner surface of the innermost sheet member 120 in the front waist region 7 and the rear waist region 8, respectively, so that the innermost sheet member 120 may be elastically contracted in the circumferential direction. The innermost sheet member 120 is formed in the crotch region 6 with the front opening 33 and the rear opening 34. The front opening 33 has the peripheral edge 33b and is positioned in front of the transverse center line Q-Q so that the wearer's external genital can be exposed in this front opening 33. The rear opening 34 has the peripheral edge 34b and is positioned behind the transverse center line Q-Q so that the wearer's anus can be exposed in this rear opening 34. Referring to Fig. 5, a pair of spacers 71 are attached to the peripheral edge 34b by which the innermost sheet member 120 is joined to itself along a lower segment 33c of the peripheral edge 33b and a lower segment 34c of the peripheral edge 34b (See Fig. 6 also).

[0043]

The bodily fluid absorbent member 122 has the bodily fluid absorbent structure 45 comprising the liquid-pervious inner sheet 2, the liquid-impervious outer sheet 3 and the bodily fluid absorbent core 4 sandwiched between the inner and outer sheets 2, 3. These inner and outer sheets 2, 3 extend outward beyond the periphery of the core 4 and put flat and bonded together outside the periphery of the core 4 wherein at least one of these inner and outer sheets 2, 3 is bonded to the innermost sheet member 120 so that the front opening 33 and the rear opening 34 may be covered with said one of the inner and outer sheets 2, 3 from outside of the innermost sheet member 120. Along the side edges 13 of the crotch region 6, the inner sheet 2, the outer sheet 3 and the innermost sheet member 120 are placed one on another and bonded together. Also along the side edges 13, the leg elastic members 14b sandwiched between the inner sheet 2 and the outer sheet 3 is bonded under tension to at least one of these two sheets 2, 3. Between the side edges 13, the inner sheet 2 and the innermost sheet member 120 are not bonded to each other so that the innermost sheet member 120 may be spaced from the inner sheet 2 in the thickness direction of the core 4 to form the body waste retaining space 31 into which urine flows through the front opening 3 and feces moves through the rear opening 34.

[0044]

Fig. 6 is a sectional view taken along the line VI-VI in Fig. 1 wherein the line VI-VI corresponds to the center line P-P extending in the front-back direction. The innermost sheet member 120 is bonded to itself along the lower segment 33c of the peripheral edge 33b defining the front opening 33 and the lower segment 34c of the peripheral edge 34b defining the rear opening 34 to form the space 50 having the dimension N in the front-back direction A between these two segments 33c, 34c. The space 50 has the dimension M in the transverse direction B (See Fig. 5) . The portion 36 of the innermost sheet member 120 defined in the front-back direction A between the lower segments 33c, 34c sags toward the lowermost portion 6a of the crotch region 6. The portion 36 of the innermost sheet member 120 may be put close to, or in contact with or joined to the lowermost portion 6a or the inner sheet 2 in the vicinity of the portion 6a. Fig. 6 exemplarily shows one of these three manners of implementation in which the portion 36 of the innermost sheet member 120 is joined to the lowermost portion 6a or the inner sheet 2 in the vicinity of the portion 6a.

[0045]
With the pants-type diaper 1 implemented as illustrated by Fig. 5 put on the wearer's body, the lower segments 33c, 34c function as dual barriers one of which prevents urine from flowing rearward along the wearer's skin in crotch region and the other of which prevents loose passage from flowing forward along the wearer' s skin in the crotch region so long as the lower segments 33c, 34c are kept in contact with the wearer's skin in the crotch region. In this way, also with the pants-type diaper 1 of Fig. 5, the wearer's skin in the vicinity of the anus would not be soiled with urine and the wearer's skin in the vicinity of the external genital would not be soiled with loose passage. The innermost sheet member 120 sags toward the lowermost portion 6a of the crotch region 6 and thereby divides the body waste retaining space 31 into front and rear halves to define the separator 20a adapted to prevent urine and feces from being mixed together on the inner sheet 2. The lower segments 33c, 34c in the pants-type diaper 1 of Fig. 5 provide the function equivalent to that of the front edge 21 and the rear edge 21 of the innermost sheet member 20 in the pants-type diaper 1 of Fig. 1.

[0046]

Details of one or more embodiments of the disposable pants-type diaper according to the present invention will be more fully understood from the description given hereunder with reference to Figs. 7-10.

[0047]

Fig. 7 is a partially cutaway perspective view of the disposable pants-type diaper 201 put on the wearer's body wherein a front-back direction, a transverse direction and a vertical direction are indicated by double-headed arrows A, B
and C extending orthogonally one to another. The diaper 201 has a crotch region 206, a front waist region 207 extending forward from the crotch region 206 and a rear waist region 208 extending rearward from the crotch region 206 wherein respective side edges of the front and rear waist regions 207, 208 are put flat and sealed together at joints 209 arranged intermittently in the vertical direction C to form a waist-opening 211 and a pair of leg-openings 212. In addition, the diaper 201 includes the innermost sheet member 220 facing the diaper's skin (not shown) and a bodily fluid-absorbent structure 222 attached to the outer surface 221b of the innermost sheet member 220. Of the innermost sheet member 220, the respective portions defining the front and rear waist regions 207, 208 are elastically contractible in the transverse direction B and most of the portion defining the crotch region 206 is not contractible in the transverse direction B

elastically as well as non-elastically. While the innermost sheet member 220 is preferably liquid-impervious over all and more preferably air-permeable and liquid-impervious over all, it is possible to form the innermost sheet member 220 in such a manner that the portions defining the front and rear waist regions 207, 208, respectively, are liquid-impervious and the portion defining the crotch region 206 is liquid-pervious.
[0048]

Referring to Fig. 7, the bodily f luid-absorbent structure 222 comprises a liquid-pervious inner sheet 223, a liquid-impervious outer sheet 224 and a core 226 sandwiched between these two sheets 223, 224 wherein the core 226 comprises, in turn, a bodily fluid-absorbent material such as fluff pulp fibers wrapped with a tissue paper. These two sheets 223, 224 extend outward from a periphery of the core 226 are bonded to each other outboard of the periphery to form a pair of side flaps 222a and a pair of end flaps 222b. These side flaps 222a and end flaps 222b are bonded to the innermost sheet member 220 (See Figs. 8 and 9) . In the crotch region 206, for example, the side flaps 222b and the innermost sheet member 220 are put flat together to define side edges 227. Along these side edges 227, leg elastic members 228 are sandwiched between the inner and outer sheets 223, 224 and bonded under tension to at least one of these sheets 223, 224 to define respective parts of leg elastic regions. In a region extending in the transverse direction B between the side edges 227, 227, the inner sheet 223 and the innermost sheet member 220 are spaced from each other in the vertical direction C to form a body waste retaining space 231. The end flaps 222b of the bodily fluid-absorbent structure 222 are bonded to the outer surface 221b of the innermost sheet member 220 and therefore no more function as the flaps.

[0049]

The innermost sheet member 220 used in such manner is formed before the transverse center line Q-Q extending in the transverse direction B to bisect a dimension of the diaper 201 in the front-back direction A with a front opening 233 and behind the transverse center line B with a rear opening 234. The front opening 233 is positioned so that the wearer's external genital can be exposed therein and the rear opening 234 is positioned so that the wearer's anus can be exposed therein. In this way, urine and feces excreted by the wearer directly flow or move into the body waste retaining space 231 not through the innermost sheet member 220. Urine and feces having flown or moved in into the body waste retaining space 2.1 is retained within the space defined between the innermost sheet member 220 and the inner sheet 223 spaced from each other and thereby prevented from coming in contact with the wearer's skin. In addition, the inner sheet 223 having absorbed such urine or feces and being in wet condition is covered with the innermost sheet member 220. The innermost sheet member 220 thus protects the wearer from uncomfortable feeling which would otherwise be experienced by the wearer due to contact with the wet inner sheet 223.

[00501 Fig. 8 is a sectional view taken along the line VIII-VIII
in Fig. 7 wherein the line VIII-VIII corresponds to the central line P-P extending in the front-back direction A to bisect a dimension of the diaper 201 in the transverse direction B. The portions of the innermost sheet member 220 in the front and rear waist regions 207, 208, respectively, are bonded to each other in parallel to the vertical center line R-R extending in the vertical direction C and bisecting the dimension of the diaper 201 in the front-back direction A to define upper segments of peripheral edges surrounding the respective leg-openings 212.

In the crotch region 206, the innermost sheet member 220 is formed with a tuck 220a. The tuck 220a is formed by bonding or sealing regions of the innermost sheet member 220 facing each other along the vertical center line R-R at a joint 237. More specifically, the innermost sheet member 220 is folded along the vertical center line R-R in its region between the front opening 233 and the rear opening 234 with the skin-facing inner surface of the innermost sheet member 220 inside. In other words, the tuck 220a extends downward from the portion of the innermost sheet member 220 spaced from the inner sheet 223 toward the inner sheet 223 to lie on the transverse center line Q-Q (See Fig. 7) . While the joint 237 for the tuck 220a is illustrated to be formed at least along the uppermost segment 238 of the tuck 220a as viewed in the vertical direction C, the joint 236 may be enlarged by an appropriate dimension toward a lower end 239 of the tuck 220a. While a dimension of the joint 237 in the transverse direction B is principally smaller than a width dimension of the crotch region 206, the dimension of the joint 237 may be enlarged unless the joint 237 prevents the diaper 201 from being smoothly put on the wearer's body. For example, in the case of the diaper 201 exclusively for baby, the dimension of the joint 237 in the transverse direction B
is preferably in a range of 10 to 70mm. The lower end 239 of the tuck 220a may be coated on its outer surface with joining means such as adhesive and joined to the inner sheet 223. In this case, the lower end 239 may be joined only along a middle portion thereof in the transverse direction B or over all to the inner sheet 223 (See Fig. 10).

[0051]

Between the innermost sheet member 220 and the inner sheet 223, the body waste retaining space 231 divided into a front half and a rear half by the tuck 220a. Specifically, the body waste retaining space 231 is divided into a front body waste retaining sub-space 231a defined before the transverse center line Q-Q and a rear body waste retaining sub-space 231b defined behind the transverse center line Q-Q. Between these two sub-spaces 231a, 231b, the tuck 220a extends upward from the inner sheet 223. The front opening 233 of the innermost sheet member 220 communicates with the inside and the outside of the front body waste retaining sub-space 231a and lets urine flow thereinto. The rear opening 234 communicates with the inside and the outside of the rear body waste retaining sub-space 231b and legs feces move thereinto.

[0052]

Fig. 9 is a partially cutaway plan view showing the diaper 201a corresponding to the diaper 201 of Figs. 7 and 8 after the front and rear waist regions 207, 208 have been unjoined from each other at the joints 209, the respective halves of the innermost sheet member 220 have been unjoined from each other at the joint 237 for the tuck 220a and then the crotch region 206 and the front and rear waist regions 207, 208 have been developed in the front-back direction A as well as in the transverse direction B. It should be noted here that the regions in the flatly developed diaper 201a which are common to those in the diaper 201 are designated by same reference numerals as those used for the diaper 201.
[0053]

The innermost sheet member 220 is contoured by a pair of side edges 221a, a front end 221b and a rear end 221c in a concave shape curved inwardly and comprises a first sheet 251 defining at least a central portion of the crotch region 206 as viewed in the front-back direction A, a second sheet 252 defining at least the front waist region 207 and a third sheet 253 defining at least the rear waist region 208 arranged in the front-back direction A. The first sheet 251 is not elastically contractible and faces the inner sheet 223 according to the embodiment of Fig. 9 and the same as the innermost sheet member 220 in shape and dimension. In other words, side edges, front end and rear end of the first sheet 251 correspond to the side edges 221a, the front end 221b and the rear end 221c of the innermost sheet member 220. The second sheet 252 is elastically contractible in the transverse direction B and bonded under tension in the transverse direction B to the inner surface of the first sheet 251 by hot melt adhesive 256 according to the embodiment of Fig. 9. The second sheet 252 is contoured by a pair of side edges 252a, a front end 252b and a rear end 252c wherein the side edges 252a and the front ends 252b substantially correspond to the side edges 251a and the front end 251b, respectively. The rear end 252c of the second sheet 252 lies in the crotch region 206 and extends across the front opening 233. The third sheet 253 also is elastically contractible in the transverse direction B and, according to the embodiment of Fig. 9, bonded under tension in the transverse direction B to the inner surface of the first sheet 251 by hot melt adhesive 256. The third sheet 253 is contoured by a pair of side edges 253a, a front end 253b and a rear end 253c wherein the side edges 253a and the rear end 253c substantially correspond to the side edges 251a and the rear end 251c of the first sheet 251. The front end 253b of the third sheet 253 lies in the crotch region 206 and extends across the rear opening 234. In this way, the innermost sheet member 220 is formed with front and rear elastic regions 271, 272 both adapted to be elastically contractible in the transverse direction B under the effect of the second sheet 252 and the third sheet 253, respectively. Between the rear end 252c of the second sheet 252 and the front end 253b of the third sheet 253 as viewed in the front-back direction A of the innermost sheet member 220, a non-elastic region 273 which is not elastically contractible in the transverse direction B is formed. A pair of regions 257 each comprising a plurality of dots gathered together on the inner surface of the first sheet 251 corresponds to the joints 237 in Fig. 8 located symmetrically about the transverse center line Q-Q.

[0054]

In the bodily fluid-absorbent structure 222, the inner sheet 223 and the outer sheet 224 sandwiching therebetween the core 226 extend outward from the periphery of the core 226 and bonded to each other outboard of the periphery of the core 226 by hot melt adhesive 258 to form the side flaps 222a and the end flaps 222b. Along the crotch region's side edges 227 in the flatly developed diaper 201a, the leg elastic members 228 are sandwiched between the inner sheet 223 and the outer sheet 224 and extend under tension in the front-back direction A.
Portions of the inner sheet 223 are bonded to the outer surface 221b of the innermost sheet member 220 by hot melt adhesive 259.

The outer sheet 224 is preferably the same as the inner sheet 223 in shape as well as in size or dimensioned to slightly larger than the inner sheet 223. When the outer sheet 224 is dimensioned to be slightly larger than the inner sheet 223, a portion of the outer sheet 224 extending outward from the periphery of the inner sheet 223 is more preferably bonded to the outer surface 221b of the innermost sheet member 220.
[0055]

To obtain the diaper 201 from the flatly developed diaper 201a of Fig. 9, the flatly developed diaper 201a is folded along the transverse center line Q-Q with the innermost sheet member 220 inside, then respective halves of the first sheet 251 are joined to each other by joining the two regions 257 to each other and simultaneously the side edges 207a, 207a of the front waist region 207 defined by the innermost sheet member 220 are joined to the side edges 208a, 208a of the rear waist region 208 defined also by the innermost sheet member 220 at the joints 209 (See Fig. 7) .

[0056]

With the diaper 201 obtained in this manner being put on the wearer's body, the innermost sheet member 220 in the crotch region 206 is spaced upward from the portion of the inner sheet 223 surrounded by the side flaps 222a and the end flaps 222b of the bodily fluid-absorbent structure 222 and thereby forms the body waste retaining space 231 adapted to prevent urine and feces from coming in contact with the wearer's skin. At the same time, the innermost sheet member 220 in the crotch region 206 functions as a barrier adapted to prevent the inner sheet 223 soiled and/or wetted with feces and/or urine from coming in contact with the wearer's skin. Furthermore, the portion of the innermost sheet member 220 defining the tuck 220a cooperates with the portions of the innermost sheet member 220 extending outward from both sides of the tuck 220a in the transverse direction B to form a partition serving as a separator adapted to prevent urine and feces from being mixed with each other. Asa consequence, in this diaper 201, fluidity of body waste would not be enhanced due to intermixture of feces and urine and the wearer's skin would not be soiled with body waste over a wide range. Furthermore, a length dimension of the innermost sheet member 220 extending along the center line P-P extending in the front-back direction A as viewed in Fig.

9 is shortened by the dimension used to form the tuck 220a as seen in Figs. 7 and 8 and therefore the innermost sheet member 220 would not be formed with remarkable gathers. The second and third sheets 252, 253 of the innermost sheet member 220 formed with the front elastic region 271 and the rear elastic region 272, respectively, are present in the front and rear waist regions 207, 208, respectively, and thereby assure high fitness of these two waist regions 207, 208 to the wearer's skin.
Portions of the second and third sheets 252, 253 forming parts of the crotch region 206 form at least parts of the respective peripheries 276, 277 of the front and rear openings 233, 234 of the first sheet 251 serve to assure elastic fitness of these peripheries to the wearer's skin around the wearer's external genital and anus and reliable flow or movement of urine or feces into the body waste retaining space 231.
[0057]

As will be apparent from the plan view of the flatly developed diaper 201a, the leg elastic members 228 extending along the side edges of the bodily fluid-absorbent structure 222 in the front-back direction A respectively intersect with the front elastic region 271 and the rear elastic region 272 provided in the innermost sheet member 220 to be contractible in the transverse direction B. In addition, as will be apparent from Fig. 7, both the front elastic region 271 and the rear elastic region 272 are substantially continuous in the circumferential direction between the respective side edges 207a, 207a and 208a, 208a of the front and rear waist regions 207, 208 joined together at the joints 209. Consequently, the front and rear elastic regions 271, 272 in the vicinity of the respective side edges 207a, 207a and 208a, 208a cooperate with the elastic members 228, 228 intersecting with the front and rear elastic regions 271, 272 to define elastic regions adapted to surround the wearer's legs.

[0058]

It should be noticed here that the innermost sheet member 220 is non-elastic in a bottom 275 of the crotch region 206 and therefore the width of this bottom 275, i.e., the dimension of the bottom 275 in the transverse direction B is never reduced due to the innermost sheet member 220. With the diaper 201 having such crotch region 206 put on the wearer's body, the side edges 227 of the crotch region 206 kept in tight contact with the wearer's inguinal region is not subject to a force in the transverse direction B functioning to move these side edges 227 of the crotch region 206 inward from the inguinal region.
Consequently, the preventive effect of the diaper 201 against sideways leakage of bodily fluids is further improved.

[0059]

Fig. 10 is a view similar to Fig. 9, illustrating one preferred embodiment of the present invention. In the flatly developed diaper 201a shown by Fig. 10, the rear end 252c of the second sheet 252 adapted to be contractible in the transverse direction B lies between front opening 233 and one of the paired regions 257 and the front end 253b of the third sheet 253 lies between the rear opening 234 and the other of the paired regions 257. With the diaper 201 obtained from such flatly developed diaper 201a put on the wearer's body, the respective portions of the front elastic region 271 and the rear elastic region 272 defining the front and rear waist regions 207, 208 are stretched in the waist-surrounding direction and the respective portions partially defining the crotch region 206 are stretched circumferentially of the respective legs.
The respective peripheral edges 276, 277 of the front opening 233 and the rear opening 234 lie over all in the front elastic region 271 and the rear elastic region 272 and, with the diaper 201 put on the wearer's body, these peripheral edges 276, 277 closely fit over all to the wearer's skin. In the flatly developed diaper 201a, the non-elastic region 273 is defined between the paired regions 257 of the innermost sheet member 220. With the diaper 201 put on the wearer's body, the bottom 275 of the crotch region 206 having the side edges 227, 227 tightly retained by the wearer's inguinal region would not contract in the transverse direction B and the side edges 227, 227 would not be disengaged from the inguinal region.

[0060]
As will be apparent from Figs. 9 and 10, in the second and third sheets 252, 253, the rear end 252c extends in the transverse direction B between the front opening 233 and one of the paired joints 237 (See Fig. 8), i.e., one of the paired regions 257 or across the front opening 233 and the front end 253b extends in the transverse direction B between the rear opening 234 and the other of the paired joints 237 or across the rear opening 234. In other words, the rear end 252c extends in the transverse direction B between a top 231t of the front opening 233 as viewed in the vertical direction C and one of the paired joints 237 and the front end 253b extends in the transverse direction B between a top 232t of the rear opening 234 and the other of the paired joints 237.

[0061]

In the flatly developed diaper 201a of Fig. 10, in order to enhance contractile force of the second sheet 252 and the third sheet 253 along the peripheral edge of the waist-opening 211 when the diaper 201 is put on the wearer's body, a plurality of thread-like elastic members 278, 279 are attached under tension to the first sheet 251. In the flatly developed diaper 201a according to this embodiment, adhesive 241 used to bond the innermost sheet member 220 to the inner sheet 223 extends across the crotch region 206 to the both side edges 227, 227.

In this case, the front body waste retaining sub-space 231a and the rear body waste retaining sub-space 231b are sealed to each other over all in the transverse direction B.

[0062]

While the innermost sheet member 220 has the same planar shape as that of the first sheet 251 according to the illustrated embodiments, such innermost sheet member 220 may be replaced by an alternately formed innermost sheet member 220 comprising a first sheet 251 defining the crotch region 206 or a part of the crotch region 206 and a second sheet 252 defining the front waist region 207 or the front waist region 207 and a part of the crotch region 206.

[0063]
While, in the diaper 201, the innermost sheet member 220 is preferably liquid-impervious and more preferably air-permeable and liquid-impervious, sheets having properties different one from another may be combined one with another to obtain the innermost sheet member 220 which is liquid-pervious in the crotch region 206 or in a part of the crotch region 206 and liquid-impervious in the front and rear waist regions 207, 208. For example, the first sheet 251 constituting the innermost sheet member 220 may be formed of a nonwoven fabric of thermoplastic synthetic fibers or a thermoplastic synthetic resin film. Alternatively, a laminated sheet of nonwoven fabric layers or a laminated sheet of nonwoven fabrics and films may be used as the first sheet 251. The second and third sheets 252, 253 may be formed, for example, of an elastically stretchable and contractible nonwoven fabric containing elastic threads such as urethane threads or an elastically stretchable and contractible film of natural or synthetic rubber. The inner sheet 223 may be formed, for example, of a liquid-pervious nonwoven fabric, a thermoplastic synthetic resin film or a composite sheet consisting of a nonwoven fabric and a film laminated one on another. The outer sheet 224 may be formed, for example, of a liquid-impervious nonwoven fabric, a thermoplastic synthetic resin film or a composite sheet consisting of a nonwoven fabric and a film laminated one on another.

[0064]

Details of one or more embodiments of the disposable pants-type diaper according to the present invention will be more fully understood from the description given hereunder with reference to Figs. 11-17.

[0065]

Fig. 11 is a partially cutaway perspective view showing the disposable pants-type diaper 301 as put on the wearer's body wherein a front-back direction, a transverse direction and a vertical direction of the diaper 301 are respectively indicated by the double-headed arrows A, B and C which are orthogonal one to another. The diaper 301 includes a pants-shaped chassis 310 comprising a liquid-pervious inner sheet 302, a liquid-impervious outer sheet 303 and a bodily f luid-absorbent core 304. The chassis 310 has a crotch region 306, a front waist region 307 extending forward from the crotch region 306 and a rear waist region 308 extending rearward from the crotch region 306. The front and rear waist regions 307, 308 are put flat and sealed together along respective pairs of side edges 307a, 307a and 308a, 308a of these waist regions 307, 308, more specifically, at joints 309 arranged intermittently in the vertical direction as viewed in Fig. 11 along these side edges 307a, 307a and 308a, 308a and thereupon a waist-opening 311 and a pair of leg-openings 312 are formed. Along a periphery 311a of the waist-opening 311, a plurality of waist elastic members 314a extending in a circumferential direction is sandwiched between the inner and outer sheets 302, 303 and bonded under tension to at least one of the inner and outer sheets 302, 303.
Along a periphery of each of the leg-openings 312, a plurality of leg elastic members 314b extending in the circumferential direction is sandwiched between the inner and outer sheets 302, 303 and bonded under tension to at least one of these inner and outer sheets 302, 303. Three components, i.e., the leg elastic members 314b and the inner and outer sheets 302, 303 cooperate together to define respective elastic regions 341 surrounding the wearer's legs. Of the diaper 301, at least the crotch region 306 includes a bodily fluid absorbent structure 345 comprising the inner and outer sheets 302, 303 and the absorbent core 304 sandwiched therebetween. The bodily fluid absorbent structure 345 extends in the front-back direction A and curves convexly downward to define a bottom portion 306a of the crotch region 306.

[0066]

Fig. 12 is a partially cutaway perspective view showing the diaper 301a as after the front and rear waist regions 307, 308 of the diaper 301 have been unsealed at the joints 309 and flatly developed as a whole in the front-back direction A as well as in the transverse direction B wherein such developed diaper 301a is shown as viewed from its inner side. In the state of such developed diaper 301a, the chassis 310 in Fig. 11 appears as a concave shaped flattened chassis 310a. The periphery 311a of the waist-opening 311 in Fig. 11 appears herein as a front end 307b and a rear end 308b of the flattened chassis 310a and the peripheries 313 of the respective leg-openings 312 appear herein as the crotch region's side edges 313b of the flattened chassis 310a. While the crotch region's side edges 313b convexly curve toward the center line P-P extending in the front-back direction A to bisect a dimension of the flattened chassis 310a in the transverse direction X, the respective pairs of side edges 307a, 307a and 308a, 308a of the front and rear waist regions 307, 308 extend substantially in parallel to this center line P-P. The absorbent core 304 also is concave shaped and is formed of a mixture 304a of fluff pulp fibers and super-absorbent polymer particles wrapped with a bodily fluid-absorbent and highly dispersant wrapping sheet 304b such as a tissue paper. In the flattened chassis 310a, the innermost sheet member 320 made of, for example, a hydrophobic nonwoven fabric, a plastic film or a composite sheet thereof, more preferably, a hydrophobic and liquid-impervious nonwoven fabric, a plastic film or a composite sheet thereof is attached to the inner sheet 302 defining the inner surface of the flattened chassis 310a in the crotch region 306 so that the innermost sheet member 320 may define a separator 320a (See Fig.
13) . Such flatly developed diaper 301a is formed symmetrically about the center line P-P extending in the front-back direction A. The lowermost portion 306a of the crotch region 306 lies on the transverse center line Q-Q bisecting a dimension of the flatly developed diaper 301a in the front-back direction A.
[0067) The innermost sheet member 320 is attached to the flattened chassis 310a so that the innermost sheet member 320 may be interposed between the inner sheet 302 and the diaper wearer's skin (not shown) when the diaper 301 is put on the wearer's body. The innermost sheet member 320 has side edges 323 respectively fixed to the crotch region's side edges 313b by hot melt adhesive 324, a front edge 321 lying before the lowermost portion 306a of the crotch region 306 and extending in the transverse direction B between the side edges 323, 323 and a rear edge 322 lying behind the lowermost portion 306a of the crotch region 306 and extending in the transverse direction B between the side edges 323, 323. The innermost sheet member 320 in the illustrated embodiment is not bonded to the inner sheet 302 and adapted to be spaced from the inner sheet 302 except the side edges 323 so that a tunnel- or pocket-like body waste retaining space 331 extending from the front edge 321 to the rear edge 322 may be defined between the innermost sheet member 320 and the inner sheet 302. Along the front edge 321 and the rear edge 322, the innermost sheet member 320 is folded to form a sleeve 321a and a sleeve 322a, respectively. These sleeves 321a, 322a contain therein a front elastic member 321b and a rear elastic member 322a attached under extension thereto, respectively, to define front elastic region 342 and a rear elastic region 343 both extending between the crotch region's side edges 313b. These elastic regions 342, 343 intersect with the elastic regions 341 of the flattened chassis 310a. A

distance Hf from the transverse center line Q-Q to the front edge 321 is substantially equal to a distance Hr from the transverse center line to the rear edge 322.

[0068]

The innermost sheet member 320 is provided on the front edge 321 with a deformation restricting sheet member 381 on the center line P-P extending in the front-back direction A. The deformation restricting sheet member 381 may be provided in the form of a block made of a sponge, a foamed polyurethane, a foamed polystyrene, a foamed polyethylene, a felt or a nonwoven fabric having a flexibility sufficient to be easily deformed under a body weight of the wearer of the diaper 301 and, more preferably, having an elastic recovery properties also sufficient for a rapid recovery after deformation. The innermost sheet member 320 is provided on the rear edge 322 with a region 382 indicated by an imaginary line. The deformation restricting sheet member 381 is bonded to this region 382 when the side edges 307a, 307a and 308a, 308a of the flattened chassis 301a are joined together to obtain the diaper 301 (See Figs. 13 and 14).

[0069]

Fig. 13 is a sectional view taken along the line XIII-XIII
in Fig. 11 and the line XIII-XIII corresponds to the center line P-P extending in the front-back direction A in Fig. 12. In the pant-shaped chassis 310, the front and rear waist regions 307, 308 are joined together along the respective side edges 307a, 307a and 308a, 308a thereof. The crotch region 306 curves in U-shape as viewed in the front-back direction A and the lowermost portion 306a of the crotch region 306 defines a bottom of this U-shaped curve. The crotch region's side edges 313b appear in Fig. 13 as the peripheral edges 313 defining the leg-openings 312. The innermost sheet member 320 has the front edge 321 and the rear edge 322 thereof bonded to each other by the deformation restricting sheet member 381 and the portion 336 shown in Fig. 12 to extend in the front-back direction A
between the front edge 321 and the rear edge 322 sags toward the lowermost portion 306a to form the separator 320a partitioning the crotch region 306 into a front half and a rear half. The deformation restricting sheet member 381 has a thickness N in the front-back direction A and a height L in the vertical direction and is attached to the innermost sheet member 320 by adhesion or sealing. The region in which the deformation restricting sheet member 381 is joined to the rear edge 322 is designated by a reference numeral 382. The separator 320a has its lower end 335 bonded to the lowermost portion 306a of the crotch region 306 by adhesive (not shown) and has height K
corresponding to a dimension from the deformation restricting sheet member 381 to the inner sheet 302 in the lowermost portion 306a of the crotch region 306. In the body waste retaining space 331 formed by cooperation of the innermost sheet member 320 with the inner sheet 302, the front edge 321 of the innermost sheet member 320 is adapted to be spaced from the inner sheet 302 and thereby to define a front opening 333 and the rear edge 322 is adapted to be spaced from the inner sheet 302 and thereby to define a rear opening 334.

[0070]

Fig. 14 is an overhead view of the diaper 301 of Fig. 11 as viewed from above the waist-opening 311 in a direction indicated by the arrows XIV-XIV in Fig. 13. The deformation restricting sheet member 381 has a width M in the transverse direction B and each of the front and rear ends 321, 322 is bisected in the transverse direction B by the deformation restricting sheet member 381 divided in two, i.e., right segments 321R, 322R adapted to be put in contact with a right leg of the diaper wearer (not shown) and left segments 321L, 322L adapted to be put in contact with a left leg of the diaper wearer. The right segments 321R, 322R cooperate with each other to define a laterally facing V-shaped space so that the wearer's right leg may be guided through this laterally facing V-shaped space. In a similar manner, the left segments 321L, 322L

cooperate with each other to define a laterally facing V-shaped space so that the wearer's left leg may be guided through this laterally facing V-shaped space. As illustrated, the respective leg-openings 312 of the chassis 310 have a right leg peripheral edge 313R and a left leg peripheral edge 313L. The respective peripheral edges 3138, 313L comprise upper segments 315a not overlapping the side edges 323 of the innermost sheet member 320 and lower segments 315b overlapping the side edges 323 and bonded thereto (See Fig. 13 also) In Fig. 14, respective ranges of these upper segments 315a and lower segments 315b are indicated by double-headed arrows G and H.
[0071]

Sequence in which the diaper 301 maybe put on the wearer' s body will be described below together with behavior of the diaper 301. First, the front and rear waist regions 307, 308 of the chassis 310 may be spaced from each other in the front-back direction A and then the waist-opening 311 may be sufficiently broadened as seen in Figs. 11 and 14. Thereby the front edge 321 of the separator 320a formed of the innermost sheet member 320 is deformed so that the right segment 321R and the left segment 321L are curved in V-shape facing forward in the front-back direction A around the deformation restricting sheet member 381. In a similar manner, the rear edge 322 is deformed so that the right segment 322R and the left segment 322L are curved in V-shape facing rearward in the front-back direction A (See Fig. 14) . Consequently, the front opening 333 and the rear opening 334 for the body waste retaining space 331 are automatically broadened (See Fig. 13) . The left segments 321L, 322L are spaced from each other in the front-back direction A
at the same moment that the right segments 321R, 322R are spaced from each other in the front-back direction A. Now the diaper wearer (not shown) may guide his or her right leg into an opening 341R for the right leg defined by the upper segment 315a of the right leg peripheral edge 3138, the right segment 321R of the front edge 321 and the right segment 322R of the rear edge 322.
Then the wearer may guide his or her right leg into the leg-opening 312 for the right leg defined by the upper segment 315a and the lower segment 315b of the right leg peripheral edge 3138. Without interruption, the wearer may guide his or her left leg into an opening 341L for the left leg defined by the upper segment 315a of the left leg peripheral edge 313L, the left segment 321L of the front edge 321 and the left-hand segment 322L of the rear edge 322. Then the wearer may guide his or her right leg into the leg-opening 312 for the left leg defined by the upper segment 315a and the lower segment 315b of the left leg peripheral edge 313L-[0072]

In the diaper 301 after it has been put on the wearer's body, the peripheral edges 313 of the respective leg-openings 312, i . e . , the right leg peripheral edge 313R and the left leg peripheral edge 313L are elastically contractible in a circumferential direction thereof, on one hand, and the front edge 321 and the rear edge 322 of the separator 320a are elastically contractible in the transverse direction B, on the other hand. With such arrangement, the upper segment 315a of the peripheral edge 313R for the right leg and the right segments 321R, 322R of the separator 320a are elastically put in close contact around the right leg in the vicinity of the right leg' s inguinal region to forma primary seal 3518 (See Fig. 14) serving to prevent leakage of bodily fluids. Below the primary seal 3518, the lower segment 315b and the upper segment 315a of the peripheral edge 313R for the right leg are integrated to form a secondary seal 352R (See Fig. 14) serving to prevent leakage of bodily fluids. Function of this secondary seal 352R is similar to that of the leg seal in the conventional pants-type diaper. The arrangement and function as have been described just above are true with respect to the left leg. Specifically, the upper segment 315a of the peripheral edge 313L for the left leg and the left segments 321L, 322L of the separator 320a are elastically put in close contact around the left leg in the vicinity of the left leg's inguinal region to form a primary seal 351L serving to prevent leakage of bodily fluids. Below the primary seal 351L, the lower segment 315b and the upper segment 315a of the peripheral edge 313L for the left leg are integrated to form a secondary seal 352L serving to prevent leakage of bodily fluids. The diaper 301 having been put on the wearer's body may be sufficiently pulled up along the body to assure that a central segment of the separator 320a as viewed in the transverse direction B along which the deformation restricting sheet member 381 is attached thereto comes in contact with the wearer's skin between the wearer's external genital and anus.

[0073]

With the diaper 301 put on the wearer's body in the state as has been described above, the portion 336 of the separator 320a is positioned to divide the wearer's crotch region into a front half and a rear half. In the front half of the wearer's crotch region, the wearer's external genital lying before the front edge 321 is exposed in the front opening 333 and, in the rear half of the wearer's crotch region, the wearer's anus lying behind the rear edge 322 is exposed in the rear opening 334.
Consequentially, it is assure that urine discharged by the wearer flows through the front opening 333 into the pocket-like body waste retaining space 331 and feces excreted by the wearer moves through the rear opening 334 into the body waste retaining space 331. In this way, it is possible for the diaper 301 to prevent urine and/or feces from coming in contact with the wearer's skin by the presence of the separator 320a. In addition, the deformation restricting sheet member 381 attached to the separator 320a functions to restrict the bodily fluid-absorbent structure from being crooked along the center line P-P in the front-back direction and thereby pressed against the diaper wearer' skin as the diaper wearer moves his or her legs tobe closed up. Thereby the deformation restricting sheet member 381 prevents the internal volume of the body waste retaining space 331 from being unacceptably reduced. The deformation restricting sheet member 381 further prevents the bodily fluid-absorbent structure 345 from moving close to the front opening 333 and/or the rear opening 334 and thereby closing these openings 333, 334.

[00741 The shape of the bodily fluid-absorbent structure 345 behaving to be crooked in this manner is indicated by imaginary lines in Fig. 11 and Fig. 15. The bodily fluid-absorbent structure 345 in Fig. 11 as well as the bodily fluid-absorbent structure 345 in Fig. 15 corresponding to the bodily fluid-absorbent structure 345 potentially behaves to move in opposite directions of the arrows E and F to be crooked and pressed in the direction of the arrow G against the wearer's skin. However, the deformation restricting sheet member 381 is able to restrict such movement.

(0075]

In response to change of the diaper wearer's posture from sitting posture to standing posture, the deformation restricting sheet member 381 accelerates the separator 320a to return from its state collapsing on the inner sheet 302 during sitting posture of the diaper wearer to the initial state in which the separator 320a extends downward from the region defined between the front and rear openings 333, 334 toward the inner sheet 302 as shown in Fig. 13 and thereby allows the separator 320a to fulfill its primary function. In the case of the separator 320a extending downward as seen in Fig. 13 having its lower end 335 bonded to the lowermost portion 306a of the crotch region 306, the separator 320a extending between the front edge 321 and the lower end 335, i . e . , between the rear edge 322 and the lower end 335 can quickly recover its normal state as seen in Fig. 13 even if the separator 320a has collapsed onto the inner sheet 302. Specifically, the deformation restricting sheet member 381 having stiffness higher than the innermost sheet member 320 is attached to the separator 320a and therefore the separator 320a can easily recover its primary state merely as the front edge 321 is pulled forward and the rear edge 322 is pulled rearward.
[0076]

The deformation restricting sheet member 381 functioning in the manner as has been described above has the width M
preferably in a range of 10 to 70mm, more preferably in a range of 30 to 60mm, the thickness N preferably in a range of 1 to 10mm, more preferably in a range of 3 to 7mm and the height L
preferably in a range of 30 to 100%, more preferably in a range of 50 to 80% of the height K of the separator 320a. If any one or more of these dimensions of the deformation restricting sheet member 381 is or are out of the ranges as have been described, feeling to wear the diaper 301 will be deteriorated and/or deformation restricting function of the deformation restricting sheet member 381 in the separator 320a and the bodily f luid-absorbent structure 345 will be insufficient. In order that the deformation restricting sheet member 381 can fulfill its primary function of enhancing the stiffness of the separator 320a in the central segment thereof as viewed in the transverse direction B, the deformation restricting sheet member 381 is formed of a material preferably having stiffness in a range of 40 to 130N, more preferably in a range of 60 to 90N based on Procedure D of Stiffness Measuring Method specified by Section 6 of JIS K 6400-2. If the stiffness is less than 40N, the deformation restricting sheet member 381 will be too flexible to fulfill its function and if the stiffness exceeds 130N, the deformation restricting sheet member 381 will make the separator 320a locally stiff beyond an allowable limit. In addition to the requirements as have been described above, the deformation restricting sheet member 381 preferably has an elastically restoring force.

[0077]

In the diaper 301, the front edge 321 of the innermost sheet member 320 defining the separator 320a partially defines the peripheral edge of the front opening 333. As viewed in the front-back direction A, the front edge 321 lies behind the wearer's external genital and positioned so that the external genital can be reliably exposed in the front opening 333. While the front edge 321 is exemplarily illustrated to extend linearly in the transverse direction B, it is also possible to form the front edge 321 to curve convexly toward the transverse center line Q-Q. The rear edge 322 of the innermost sheet member 320 partially defines the peripheral edge of the rear opening 334.

As viewed in the front-back direction A, the rear edge 322 lies before the wearer's anus and positioned so that the anus can reliably face the rear opening 334. While such rear edge 322 is exemplarily illustrated to extend linearly in the transverse direction B, it is possible to form the rear edge 322 to curve convexly toward the transverse center line Q-Q.

[0078]

In the crotch region 306 of the flattened chassis 310a shown by Fig. 12, the inner and outer sheets 302, 303 put flat together define side flaps 325 outside the liquid-absorbent core 304. When the crotch region 306 is curved in U-shape under contraction of the elastic regions 341 and thereupon the diaper 301 is put into the state as illustrated by Fig. 11, the side flaps 325 behave to raise themselves along side edges 304c of the core 304 in the vicinity of the transverse center line Q-Q, i . e . , in the vicinity of the lowermost portion 306a of the crotch region 306. The innermost sheet member 320 having the side edges 323 bonded to the inner surface of the elastic regions 341 pulls the side flaps 325 inward in the transverse direction of the diaper 301, i.e., toward the center line P-P extending in the front-back direction as the waist-opening 311 is broadened. In consequence, the behavior of the side flaps 325 to raise themselves is further enhanced. Such behavior of the side flaps 325 becomes further significant as the front edge 321 and the rear edge 322 elastically contract. The side flaps 325 having such behavior come in close contact with the wearer's thighs from below with respect to the diaper 301 and thereby effectively prevent bodily fluids from leaking out along the wearer's thighs.

[0079]

To implement the present invention, a liquid-pervious sheet material such as a nonwoven fabric or a perforated plastic film may be used as the inner sheet 302. A liquid-impervious sheet material such as a plastic film or a composite sheet consisting of a plastic film and a nonwoven fabric may be used as the outer sheet 303. Fluff pulp fibers or a mixture of fluff pulp fibers and super-absorbent polymer particles wrapped with an appropriate sheet material such as a tissue paper may be used as the liquid-absorbent core 304. A hydrophobic sheet material such as a nonwoven fabric or a plastic film, more preferably, a hydrophobic and liquid-impervious sheet material may be used as the innermost sheet member 320. While the innermost sheet member 320 are preferably provided along the front edge 321 and the rear edge 322 with the elastic members 321b, 322b attached under tension thereto so that the innermost sheet member 320 may be elastically contracted, it is possible to eliminate use of the elastic members 321b, 322b by using an elastic sheet material adapted to be elastically and contracted in the transverse direction B as the innermost sheet member 320. It should be appreciated that the present invention includes an embodiment according to which both the front edge 321 and the rear edge 322 are not elastically contractible in the transverse direction B.

[0080]
Fig. 15 is a partially cutaway perspective view of one preferred embodiment of the diaper 301 according to the present invention. Regions and members of this embodiment similar to those in the diaper 301 of Fig. 11 are designated with similar reference numerals. Specifically, the diaper 301 of Fig. 15 also has the crotch region 306, the front waist region 307 and the rear waist region 308 wherein the side edges 307a, 307a and 308a, 308a of the front and rear waist regions 307, 308 are put flat and sealed together at the joints 309 arranged intermittently in the vertical direction to form the waist-opening 311 and a pair of the leg-openings 312. The diaper 301 according to this embodiment also includes the innermost sheet member 320 facing the wearer' skin (not shown) and a bodily fluid absorbent member 345 attached to the outer surface 320b of the innermost sheet member 320 wherein these innermost sheet member 120 and the bodily fluid absorbent member 122 are integrated with each other to form the pant-shaped chassis 310. The innermost sheet member 320 is preferably hydrophobic, more preferably hydrophobic and liquid-impervious. Elastic sheet pieces 352 are bonded under tension to the inner surface of the innermost sheet member 320 in the front waist region 307 and the rear waist region 308, respectively, so that the innermost sheet member 320 may be elastically contracted in the circumferential direction. The innermost sheet member 320 is formed in the crotch region 306 with the front opening 333 and the rear opening 334. The front opening 333 has the peripheral edge 333b and is positioned in front of the transverse center line Q-Q so that the wearer's external genital can be exposed in this front opening 333. The rear opening 334 has the peripheral edge 334b and is positioned behind the transverse center line Q-Q so that the wearer's anus can be exposed in this rear opening 334. Referring to Fig. 15, the deformation restricting sheet member 381 interposed between the lower segment 334b of the peripheral edge 334b and the lower segments 334c of the peripheral edge 334b both of the innermost sheet member 320 to join these two segments 333c, 334c is shown (See Fig. 16 also) . The imaginary lines J indicate the potential behavior of the bodily fluid-absorbent structure 122 in the crotch region 306 moving inward in opposite directions of the arrows E and F and thereby being crooked so as to be pressed in a direction of the arrow G against the diaper wearer's skin.
The deformation restricting sheet member 381 is effective to restrict such potential behavior.
[0081]

The bodily fluid absorbent member 122 has the bodily fluid absorbent structure 345 comprising the liquid-pervious inner sheet 302, the liquid-impervious outer sheet 303 and the bodily fluid absorbent core 304 sandwiched the inner and outer sheets 302, 303. These inner and outer sheets 302, 303 extend outward beyond the periphery of the core 304 and put flat and bonded together outside the periphery of the core 304 wherein at least one of these inner and outer sheets 302, 303 is bonded to the innermost sheet member 320 so that the front opening 333 and the rear opening 334 may be covered with said one of the inner and outer sheets 302, 303 from outside of the innermost sheet member 320. Along the side edges 313 of the crotch region 306, the inner sheet 302, the outer sheet 303 and the innermost sheet member 320 are placed one on another and bonded together. Also along the side edges 313, the leg elastic members 314b sandwiched between the inner sheet 302 and the outer sheet 303 is bonded under tension to at least one of these two sheets 302, 303. Between the side edges 313, the inner sheet 302 and the innermost sheet member 320 are not bonded to each other so that the innermost sheet member 320 may be spaced from the inner sheet 302 in the thickness direction of the core 304 to form the body waste retaining space 331 into which urine flows through the front opening 303 and feces moves through the rear opening 334.
[0082]

Fig. 16 is a sectional view taken along the line XVI-XVI
in Fig. 11 wherein the line XVI-XVI corresponds to the center line P-P extending in the front-back direction. The innermost sheet member 320 is indirectly bonded to itself along the lower segment 333c of the peripheral edge 333b defining the front opening 333 and the lower segment 334c of the peripheral edge 334b defining the rear opening 334 via the deformation restricting sheet member 381 having the thickness N and the height K. The portion 336 of the innermost sheet member 320 defined in the front-back directionAbetween the lower segments 333c, 334c sags down toward the lowermost portion 306a of the crotch region 306. The portion 336 of the innermost sheet member 320 extending between the lower segments 333c, 334c in the front-back direction A extends downward toward the lower most portion 306a of the crotch region 306 and the lower end 335 of the innermost sheet member 320 is joined to the inner sheet 302.

[0083]

Fig. 17 is a view similar to Fig. 16, showing another preferred embodiment of the present invention. In the diaper 301 shown by Fig. 17, the innermost sheet member 320 is directly bonded to itself to form the separator 320a. The deformation restricting sheet member 381 is attached to the rear surface 383 of the separator 320a. With this alternative arrangement, there is possibility that loose passage flowing into the body waste retaining space comes in direct contact with the deformation restricting sheet member 381. Considering such possibility, it will be advantageous to form the deformation restricting sheet member 381 by a sponge having interconnected cells or a sheet material having many voids such as a nonwoven fabric of crimped conjugate fibers since loose passage can be trapped by these voids. By trapping loose passage of high fluidity in the voids, loose passage would be prevented from flowing out of the rear opening and soiling the wearer's skin.

It should be appreciated here that the deformation restricting sheet member 381 may be attached not to the rear surface 383 but to the front surface 382 of the separator 320a without departing from the scope of the present invention.

Claims

[1] A disposable pants-type diaper having a front-back direction, a transverse direction and a vertical direction being orthogonal one to another and comprising a crotch region, a front waist region extending forward from said crotch region and a rear waist region extending rearward from said crotch region wherein said crotch region includes a bodily fluid absorbent structure comprising a liquid-pervious inner sheet, a liquid-impervious outer sheet and a bodily fluid absorbent core sandwiched between said inner and outer sheets and curved with inner sheet inside and said crotch region is additionally formed with a separator adapted to separate urine and feces from each other, said disposable pants-type diaper being characterized in that:

an innermost sheet member bonded to said inner sheet to be interposed between a pants-type diaper wearer's skin and said inner sheet is adapted to be partially spaced upward from said inner sheet in said vertical direction and thereby to form a body waste retaining space wherein said innermost sheet member includes a front opening allowing urine to flow into said body waste retaining space and a rear opening allowing feces to move into said body waste retaining space;

a portion of said innermost sheet member extending between said front opening and said rear opening in said front-back direction sags toward a lowermost portion of said crotch region and is bonded to itself in segments thereof opposed to each other in said front-back direction to form said separator.
[2] The pants-type diaper defined by Claim 1 wherein said innermost sheet member is bonded to said inner sheet and segments of said innermost sheet member defining at least respective parts of peripheral edges of said front opening and said rear opening and opposed to each other in said front-back direction are bonded together via a pair of spacers spaced from each other in said transverse direction to define a space having a required dimension.
[3] The pants-type diaper defined by Claim 2 wherein each of said two spacers is formed of a flexible and elastic material.
[4] The pants-type diaper defined by Claim 2 or 3 wherein each of said two spacers has a dimension in a range of 1 to 30mm in said front-back direction and is spaced from each other by a distance in a range of 5 to 70mm in said transverse direction.
[5] The pants-type diaper defined by Claim 1 wherein said bodily fluid-absorbent structure has side flaps formed outboard of said core in said transverse direction and end flaps formed outboard of said core in said vertical direction;

a region of said innermost sheet member extending between said front opening and said rear opening is folded along a fold line extending in said transverse direction and defined by a center line bisecting a dimension of said diaper in said transverse direction with a skin-facing surface of said innermost sheet member inside so that said region extending between said front and rear opening and folded to face itself and partially bonded together and said innermost sheet member extends downward from this bonded region toward said inner sheet in said vertical direction to form said separator; and said innermost sheet member further includes elastic regions adapted to be elastically contractible and respectively defined between said region facing itself in said front-back direction and partially bonded together and a top of said front opening as viewed in said vertical direction and between said region facing itself in said front-back direction and partially bonded together and a top of said rear opening as viewed in said vertical direction, on one hand, and a non-elastic region defined by a portion extending downward from said bonded regions, on other hand.
[6] The diaper defined by Claim 5 wherein said elastic regions extend in said transverse direction in said crotch region and joined under tension to said side flaps of said bodily fluid-absorbent structure.
[7] The diaper defined by Claim 5 or 6 wherein said innermost sheet member is pant-shaped.
[8] The diaper defined by any one of Claims 5 through 7 wherein said side flaps are provided with elastic members extending in said front-back direction attached under tension thereto and said elastic regions intersect and overlap said elastic members.
[9] The diaper defined by Claim 8 wherein said elastic regions and said elastic members are bonded together in regions of intersecting and overlapping.
[10] The pants-type diaper defined by Claim 1 wherein a portion of said innermost sheet member extending in said front-back direction between said front opening and said rear opening is folded to be opposed to each other in said front-back direction and directly or indirectly bonded to itself along a center line extending in said transverse direction and bisecting a dimension of said diaper in said front-back direction so that said portion droops down toward said crotch region and a lower end thereof is joined to said inner sheet to form said separator;
and said separator is provided along said center line with a sheet member having a thickness in said front-back direction in a range of 1 to 10mm, a width in said transverse direction in a range of 10 to 70mm and a height in said vertical direction in a range of 30 to 100% of a dimension of said separator in said vertical direction and functioning to restrict a degree of deformation potentially occurring in said separator formed of said innermost sheet material.
[11] The diaper defined by Claim 10 wherein said sheet member has a level of stiffness in a range of 40 to 130N based on Procedure D of Stiffness Measuring Method specified by Section 6 of JIS K 6400-2.
[12] The diaper defined by Claim 10 or 11 wherein said sheet member is attached to said separator on a front surface of said separator, a rear surface of said separator or between said opposed and joined portions of said innermost sheet member.